#include "WINGsP.h"

char *WMListDidScrollNotification = "WMListDidScrollNotification";
char *WMListSelectionDidChangeNotification = "WMListSelectionDidChangeNotification";

typedef struct W_List {
    W_Class widgetClass;
    W_View *view;

    WMArray *items; 	    /* list of WMListItem */
    WMArray *selectedItems; /* list of selected WMListItems */

    short itemHeight;

    int topItem;	    /* index of first visible item */

    short fullFitLines;	    /* no of lines that fit entirely */

    void *clientData;
    WMAction *action;
    void *doubleClientData;
    WMAction *doubleAction;

    WMListDrawProc *draw;

    WMHandlerID	*idleID;    /* for updating the scroller after adding elements */

    WMHandlerID	*selectID;  /* for selecting items in list while scrolling */

    WMScroller *vScroller;

    struct {
        unsigned int allowMultipleSelection:1;
        unsigned int allowEmptySelection:1;
        unsigned int userDrawn:1;
        unsigned int userItemHeight:1;
        unsigned int dontFitAll:1;     /* 1 = last item won't be fully visible */
        unsigned int redrawPending:1;
        unsigned int buttonPressed:1;
        unsigned int buttonWasPressed:1;
    } flags;
} List;



#define DEFAULT_WIDTH	150
#define DEFAULT_HEIGHT	150

#define SCROLL_DELAY    100


static void destroyList(List *lPtr);
static void paintList(List *lPtr);


static void handleEvents(XEvent *event, void *data);
static void handleActionEvents(XEvent *event, void *data);

static void updateScroller(void *data);
static void scrollForwardSelecting(void *data);
static void scrollBackwardSelecting(void *data);

static void vScrollCallBack(WMWidget *scroller, void *self);

static void toggleItemSelection(WMList *lPtr, int index);

static void updateGeometry(WMList *lPtr);
static void didResizeList();

static void unselectAllListItems(WMList *lPtr, WMListItem *exceptThis);


W_ViewDelegate _ListViewDelegate = {
    NULL,
    NULL,
    didResizeList,
    NULL,
    NULL
};


static void
releaseItem(void *data)
{
    WMListItem *item = (WMListItem*)data;

    if (item->text)
        wfree(item->text);
    wfree(item);
}


WMList*
WMCreateList(WMWidget *parent)
{
    List *lPtr;
    W_Screen *scrPtr = W_VIEW(parent)->screen;

    lPtr = wmalloc(sizeof(List));
    memset(lPtr, 0, sizeof(List));

    lPtr->widgetClass = WC_List;

    lPtr->view = W_CreateView(W_VIEW(parent));
    if (!lPtr->view) {
        wfree(lPtr);
        return NULL;
    }
    lPtr->view->self = lPtr;

    lPtr->view->delegate = &_ListViewDelegate;

    WMCreateEventHandler(lPtr->view, ExposureMask|StructureNotifyMask
                         |ClientMessageMask, handleEvents, lPtr);

    WMCreateEventHandler(lPtr->view, ButtonPressMask|ButtonReleaseMask
                         |EnterWindowMask|LeaveWindowMask|ButtonMotionMask,
                         handleActionEvents, lPtr);

    lPtr->itemHeight = WMFontHeight(scrPtr->normalFont) + 1;

    lPtr->items = WMCreateArrayWithDestructor(4, releaseItem);
    lPtr->selectedItems = WMCreateArray(4);

    /* create the vertical scroller */
    lPtr->vScroller = WMCreateScroller(lPtr);
    WMMoveWidget(lPtr->vScroller, 1, 1);
    WMSetScrollerArrowsPosition(lPtr->vScroller, WSAMaxEnd);

    WMSetScrollerAction(lPtr->vScroller, vScrollCallBack, lPtr);

    /* make the scroller map itself when it's realized */
    WMMapWidget(lPtr->vScroller);

    W_ResizeView(lPtr->view, DEFAULT_WIDTH, DEFAULT_HEIGHT);

    return lPtr;
}


void
WMSetListAllowMultipleSelection(WMList *lPtr, Bool flag)
{
    lPtr->flags.allowMultipleSelection = flag ? 1 : 0;
}


void
WMSetListAllowEmptySelection(WMList *lPtr, Bool flag)
{
    lPtr->flags.allowEmptySelection = flag ? 1 : 0;
}


static int
comparator(const void *a, const void *b)
{
    return (strcmp((*(WMListItem**)a)->text, (*(WMListItem**)b)->text));
}


void
WMSortListItems(WMList *lPtr)
{
    WMSortArray(lPtr->items, comparator);

    paintList(lPtr);
}



void
WMSortListItemsWithComparer(WMList *lPtr, WMCompareDataProc *func)
{
    WMSortArray(lPtr->items, func);

    paintList(lPtr);
}



WMListItem*
WMInsertListItem(WMList *lPtr, int row, char *text)
{
    WMListItem *item;

    CHECK_CLASS(lPtr, WC_List);

    item = wmalloc(sizeof(WMListItem));
    memset(item, 0, sizeof(WMListItem));
    item->text = wstrdup(text);

    row = WMIN(row, WMGetArrayItemCount(lPtr->items));

    if (row < 0)
        WMAddToArray(lPtr->items, item);
    else
        WMInsertInArray(lPtr->items, row, item);

    /* update the scroller when idle, so that we don't waste time
     * updating it when another item is going to be added later */
    if (!lPtr->idleID) {
        lPtr->idleID = WMAddIdleHandler((WMCallback*)updateScroller, lPtr);
    }

    return item;
}


void
WMRemoveListItem(WMList *lPtr, int row)
{
    WMListItem *item;
    int topItem = lPtr->topItem;
    int selNotify = 0;

    CHECK_CLASS(lPtr, WC_List);

    /*wassertr(row>=0 && row<WMGetArrayItemCount(lPtr->items));*/
    if (row<0 || row>=WMGetArrayItemCount(lPtr->items))
        return;

    item = WMGetFromArray(lPtr->items, row);
    if (item->selected) {
        WMRemoveFromArray(lPtr->selectedItems, item);
        selNotify = 1;
    }

    if (row <= lPtr->topItem+lPtr->fullFitLines+lPtr->flags.dontFitAll)
        lPtr->topItem--;
    if (lPtr->topItem < 0)
        lPtr->topItem = 0;

    WMDeleteFromArray(lPtr->items, row);

    if (!lPtr->idleID) {
        lPtr->idleID = WMAddIdleHandler((WMCallback*)updateScroller, lPtr);
    }
    if (lPtr->topItem != topItem) {
        WMPostNotificationName(WMListDidScrollNotification, lPtr, NULL);
    }
    if (selNotify) {
        WMPostNotificationName(WMListSelectionDidChangeNotification, lPtr, NULL);
    }
}


WMListItem*
WMGetListItem(WMList *lPtr, int row)
{
    return WMGetFromArray(lPtr->items, row);
}


WMArray*
WMGetListItems(WMList *lPtr)
{
    return lPtr->items;
}


void
WMSetListUserDrawProc(WMList *lPtr, WMListDrawProc *proc)
{
    lPtr->flags.userDrawn = 1;
    lPtr->draw = proc;
}


void
WMSetListUserDrawItemHeight(WMList *lPtr, unsigned short height)
{
    assert(height > 0);

    lPtr->flags.userItemHeight = 1;
    lPtr->itemHeight = height;

    updateGeometry(lPtr);
}


void
WMClearList(WMList *lPtr)
{
    int selNo = WMGetArrayItemCount(lPtr->selectedItems);

    WMEmptyArray(lPtr->selectedItems);
    WMEmptyArray(lPtr->items);

    lPtr->topItem = 0;

    if (!lPtr->idleID) {
        WMDeleteIdleHandler(lPtr->idleID);
        lPtr->idleID = NULL;
    }
    if (lPtr->selectID) {
        WMDeleteTimerHandler(lPtr->selectID);
        lPtr->selectID = NULL;
    }
    if (lPtr->view->flags.realized) {
        updateScroller(lPtr);
    }
    if (selNo > 0) {
        WMPostNotificationName(WMListSelectionDidChangeNotification, lPtr, NULL);
    }
}


void
WMSetListAction(WMList *lPtr, WMAction *action, void *clientData)
{
    lPtr->action = action;
    lPtr->clientData = clientData;
}


void
WMSetListDoubleAction(WMList *lPtr, WMAction *action, void *clientData)
{
    lPtr->doubleAction = action;
    lPtr->doubleClientData = clientData;
}


WMArray*
WMGetListSelectedItems(WMList *lPtr)
{
    return lPtr->selectedItems;
}


WMListItem*
WMGetListSelectedItem(WMList *lPtr)
{
    return WMGetFromArray(lPtr->selectedItems, 0);
}


int
WMGetListSelectedItemRow(WMList *lPtr)
{
    WMListItem *item = WMGetFromArray(lPtr->selectedItems, 0);

    return (item!=NULL ? WMGetFirstInArray(lPtr->items, item) : WLNotFound);
}


int
WMGetListItemHeight(WMList *lPtr)
{
    return lPtr->itemHeight;
}


void
WMSetListPosition(WMList *lPtr, int row)
{
    lPtr->topItem = row;
    if (lPtr->topItem + lPtr->fullFitLines > WMGetArrayItemCount(lPtr->items))
        lPtr->topItem = WMGetArrayItemCount(lPtr->items) - lPtr->fullFitLines;

    if (lPtr->topItem < 0)
        lPtr->topItem = 0;

    if (lPtr->view->flags.realized)
        updateScroller(lPtr);
}


void
WMSetListBottomPosition(WMList *lPtr, int row)
{
    if (WMGetArrayItemCount(lPtr->items) > lPtr->fullFitLines) {
        lPtr->topItem = row - lPtr->fullFitLines;
        if (lPtr->topItem < 0)
            lPtr->topItem = 0;
        if (lPtr->view->flags.realized)
            updateScroller(lPtr);
    }
}


int
WMGetListNumberOfRows(WMList *lPtr)
{
    return WMGetArrayItemCount(lPtr->items);
}


int
WMGetListPosition(WMList *lPtr)
{
    return lPtr->topItem;
}


Bool
WMListAllowsMultipleSelection(WMList *lPtr)
{
    return lPtr->flags.allowMultipleSelection;
}


Bool
WMListAllowsEmptySelection(WMList *lPtr)
{
    return lPtr->flags.allowEmptySelection;
}


static void
scrollByAmount(WMList *lPtr, int amount)
{
    int itemCount = WMGetArrayItemCount(lPtr->items);

    if ((amount < 0 && lPtr->topItem > 0) ||
        (amount > 0 && (lPtr->topItem + lPtr->fullFitLines < itemCount))) {

        lPtr->topItem += amount;
        if (lPtr->topItem < 0)
            lPtr->topItem = 0;
        if (lPtr->topItem + lPtr->fullFitLines > itemCount)
            lPtr->topItem = itemCount - lPtr->fullFitLines;

        updateScroller(lPtr);
    }
}


static void
vScrollCallBack(WMWidget *scroller, void *self)
{
    WMList *lPtr = (WMList*)self;
    int height;
    int oldTopItem = lPtr->topItem;
    int itemCount = WMGetArrayItemCount(lPtr->items);

    height = lPtr->view->size.height - 4;

    switch (WMGetScrollerHitPart((WMScroller*)scroller)) {
    case WSDecrementLine:
        scrollByAmount(lPtr, -1);
        break;

    case WSIncrementLine:
        scrollByAmount(lPtr, 1);
        break;

    case WSDecrementPage:
        scrollByAmount(lPtr, -lPtr->fullFitLines+(1-lPtr->flags.dontFitAll)+1);
        break;

    case WSIncrementPage:
        scrollByAmount(lPtr, lPtr->fullFitLines-(1-lPtr->flags.dontFitAll)-1);
        break;

    case WSDecrementWheel:
        scrollByAmount(lPtr, -lPtr->fullFitLines / 3);
        break;

    case WSIncrementWheel:
        scrollByAmount(lPtr, lPtr->fullFitLines / 3);
        break;

    case WSKnob:
        lPtr->topItem = WMGetScrollerValue(lPtr->vScroller) *
            (float)(itemCount - lPtr->fullFitLines);

        if (oldTopItem != lPtr->topItem)
            paintList(lPtr); /* use updateScroller(lPtr) here? -Dan */
        break;

    case WSKnobSlot:
    case WSNoPart:
    default:
        /* do nothing */
        break;
    }

    if (lPtr->topItem != oldTopItem)
        WMPostNotificationName(WMListDidScrollNotification, lPtr, NULL);
}


static void
paintItem(List *lPtr, int index)
{
    WMView *view = lPtr->view;
    W_Screen *scr = view->screen;
    int width, height, x, y;
    WMListItem *itemPtr;

    itemPtr = WMGetFromArray(lPtr->items, index);

    width = lPtr->view->size.width - 2 - 19;
    height = lPtr->itemHeight;
    x = 19;
    y = 2 + (index-lPtr->topItem) * lPtr->itemHeight + 1;

    if (lPtr->flags.userDrawn) {
        WMRect rect;
        int flags;

        rect.size.width = width;
        rect.size.height = height;
        rect.pos.x = x;
        rect.pos.y = y;

        flags = itemPtr->uflags;
        if (itemPtr->disabled)
            flags |= WLDSDisabled;
        if (itemPtr->selected)
            flags |= WLDSSelected;
        if (itemPtr->isBranch)
            flags |= WLDSIsBranch;

        if (lPtr->draw)
            (*lPtr->draw)(lPtr, index, view->window, itemPtr->text, flags,
                          &rect);
    } else {
        if (itemPtr->selected) {
            XFillRectangle(scr->display, view->window, WMColorGC(scr->white),
                           x, y, width, height);
        } else {
            XClearArea(scr->display, view->window, x, y, width, height, False);
        }

        W_PaintText(view, view->window, scr->normalFont,  x+4, y, width,
                    WALeft, WMColorGC(scr->black), False,
                    itemPtr->text, strlen(itemPtr->text));
    }

    if ((index-lPtr->topItem+lPtr->fullFitLines)*lPtr->itemHeight >
        lPtr->view->size.height-2) {
        W_DrawRelief(lPtr->view->screen, lPtr->view->window, 0, 0,
                     lPtr->view->size.width, lPtr->view->size.height,
                     WRSunken);
    }
}



static void
paintList(List *lPtr)
{
    W_Screen *scrPtr = lPtr->view->screen;
    int i, lim;

    if (!lPtr->view->flags.mapped)
        return;

    if (WMGetArrayItemCount(lPtr->items) > 0) {
        if (lPtr->topItem+lPtr->fullFitLines+lPtr->flags.dontFitAll
            > WMGetArrayItemCount(lPtr->items)) {

            lim = WMGetArrayItemCount(lPtr->items) - lPtr->topItem;
            XClearArea(scrPtr->display, lPtr->view->window, 19,
                       2+lim*lPtr->itemHeight, lPtr->view->size.width-21,
                       lPtr->view->size.height-lim*lPtr->itemHeight-3, False);
        } else {
            lim = lPtr->fullFitLines + lPtr->flags.dontFitAll;
        }
        for (i = lPtr->topItem; i < lPtr->topItem + lim; i++) {
            paintItem(lPtr, i);
        }
    } else {
        XClearWindow(scrPtr->display, lPtr->view->window);
    }
    W_DrawRelief(scrPtr, lPtr->view->window, 0, 0, lPtr->view->size.width,
                 lPtr->view->size.height, WRSunken);
}

#if 0
static void
scrollTo(List *lPtr, int newTop)
{

}
#endif

static void
updateScroller(void *data)
{
    List *lPtr = (List*)data;

    float knobProportion, floatValue, tmp;
    int count = WMGetArrayItemCount(lPtr->items);

    if (lPtr->idleID)
        WMDeleteIdleHandler(lPtr->idleID);
    lPtr->idleID = NULL;

    paintList(lPtr);

    if (count == 0 || count <= lPtr->fullFitLines)
        WMSetScrollerParameters(lPtr->vScroller, 0, 1);
    else {
        tmp = lPtr->fullFitLines;
        knobProportion = tmp/(float)count;

        floatValue = (float)lPtr->topItem/(float)(count - lPtr->fullFitLines);

        WMSetScrollerParameters(lPtr->vScroller, floatValue, knobProportion);
    }
}


static void
scrollForwardSelecting(void *data)
{
    List *lPtr = (List*)data;
    int lastSelected;

    lastSelected = lPtr->topItem+lPtr->fullFitLines+lPtr->flags.dontFitAll-1;

    if (lastSelected >= WMGetArrayItemCount(lPtr->items)-1) {
        lPtr->selectID = NULL;
        if (lPtr->flags.dontFitAll)
            scrollByAmount(lPtr, 1);
        return;
    }

    /* selecting NEEDS to be done before scrolling to avoid flickering */
    if (lPtr->flags.allowMultipleSelection) {
        WMListItem *item;
        WMRange range;

        item = WMGetFromArray(lPtr->selectedItems, 0);
        range.position = WMGetFirstInArray(lPtr->items, item);
        if (lastSelected+1 >= range.position) {
            range.count = lastSelected - range.position + 2;
        } else {
            range.count = lastSelected - range.position;
        }
        WMSetListSelectionToRange(lPtr, range);
    } else {
        WMSelectListItem(lPtr, lastSelected+1);
    }
    scrollByAmount(lPtr, 1);

    lPtr->selectID = WMAddTimerHandler(SCROLL_DELAY, scrollForwardSelecting,
                                       lPtr);
}


static void
scrollBackwardSelecting(void *data)
{
    List *lPtr = (List*)data;

    if (lPtr->topItem < 1) {
        lPtr->selectID = NULL;
        return;
    }

    /* selecting NEEDS to be done before scrolling to avoid flickering */
    if (lPtr->flags.allowMultipleSelection) {
        WMListItem *item;
        WMRange range;

        item = WMGetFromArray(lPtr->selectedItems, 0);
        range.position = WMGetFirstInArray(lPtr->items, item);
        if (lPtr->topItem-1 >= range.position) {
            range.count = lPtr->topItem - range.position;
        } else {
            range.count = lPtr->topItem - range.position - 2;
        }
        WMSetListSelectionToRange(lPtr, range);
    } else {
        WMSelectListItem(lPtr, lPtr->topItem-1);
    }
    scrollByAmount(lPtr, -1);

    lPtr->selectID = WMAddTimerHandler(SCROLL_DELAY, scrollBackwardSelecting,
                                       lPtr);
}


static void
handleEvents(XEvent *event, void *data)
{
    List *lPtr = (List*)data;

    CHECK_CLASS(data, WC_List);


    switch (event->type) {
    case Expose:
        if (event->xexpose.count!=0)
            break;
        paintList(lPtr);
        break;

    case DestroyNotify:
        destroyList(lPtr);
        break;

    }
}


static int
matchTitle(void *item, void *title)
{
    return (strcmp(((WMListItem*)item)->text, (char*)title)==0 ? 1 : 0);
}


int
WMFindRowOfListItemWithTitle(WMList *lPtr, char *title)
{
    return WMFindInArray(lPtr->items, matchTitle, title);
}


void
WMSelectListItem(WMList *lPtr, int row)
{
    WMListItem *item;

    if (row >= WMGetArrayItemCount(lPtr->items))
        return;

    if (row < 0) {
        /* row = -1 will deselects all for backward compatibility.
         * will be removed later. -Dan */
        WMUnselectAllListItems(lPtr);
        return;
    }

    item = WMGetFromArray(lPtr->items, row);
    if (item->selected)
        return;           /* Return if already selected */

    if (!lPtr->flags.allowMultipleSelection) {
        /* unselect previous selected items */
        unselectAllListItems(lPtr, NULL);
    }

    /* select item */
    item->selected = 1;
    WMAddToArray(lPtr->selectedItems, item);

    if (lPtr->view->flags.mapped && row>=lPtr->topItem
        && row<=lPtr->topItem+lPtr->fullFitLines) {
        paintItem(lPtr, row);
    }

    WMPostNotificationName(WMListSelectionDidChangeNotification, lPtr, NULL);
}


void
WMUnselectListItem(WMList *lPtr, int row)
{
    WMListItem *item = WMGetFromArray(lPtr->items, row);

    if (!item || !item->selected)
        return;

    if (!lPtr->flags.allowEmptySelection &&
        WMGetArrayItemCount(lPtr->selectedItems) <= 1) {
        return;
    }

    item->selected = 0;
    WMRemoveFromArray(lPtr->selectedItems, item);

    if (lPtr->view->flags.mapped && row>=lPtr->topItem
        && row<=lPtr->topItem+lPtr->fullFitLines) {
        paintItem(lPtr, row);
    }

    WMPostNotificationName(WMListSelectionDidChangeNotification, lPtr, NULL);
}


void
WMSelectListItemsInRange(WMList *lPtr, WMRange range)
{
    WMListItem *item;
    int position = range.position, k = 1, notify = 0;
    int total = WMGetArrayItemCount(lPtr->items);

    if (!lPtr->flags.allowMultipleSelection)
        return;
    if (range.count==0)
        return; /* Nothing to select */

    if (range.count < 0) {
        range.count = -range.count;
        k = -1;
    }

    for (; range.count>0 && position>=0 && position<total; range.count--) {
        item = WMGetFromArray(lPtr->items, position);
        if (!item->selected) {
            item->selected = 1;
            WMAddToArray(lPtr->selectedItems, item);
            if (lPtr->view->flags.mapped && position>=lPtr->topItem
                && position<=lPtr->topItem+lPtr->fullFitLines) {
                paintItem(lPtr, position);
            }
            notify = 1;
        }
        position += k;
    }

    if (notify) {
        WMPostNotificationName(WMListSelectionDidChangeNotification, lPtr, NULL);
    }
}


void
WMSetListSelectionToRange(WMList *lPtr, WMRange range)
{
    WMListItem *item;
    int mark1, mark2, i, k;
    int position = range.position, notify = 0;
    int total = WMGetArrayItemCount(lPtr->items);

    if (!lPtr->flags.allowMultipleSelection)
        return;

    if (range.count==0) {
        WMUnselectAllListItems(lPtr);
        return;
    }

    if (range.count < 0) {
        mark1 = range.position + range.count + 1;
        mark2 = range.position + 1;
        range.count = -range.count;
        k = -1;
    } else {
        mark1 = range.position;
        mark2 = range.position + range.count;
        k = 1;
    }
    if (mark1 > total)
        mark1 = total;
    if (mark2 < 0)
        mark2 = 0;

    WMEmptyArray(lPtr->selectedItems);

    for (i=0; i<mark1; i++) {
        item = WMGetFromArray(lPtr->items, i);
        if (item->selected) {
            item->selected = 0;
            if (lPtr->view->flags.mapped && i>=lPtr->topItem
                && i<=lPtr->topItem+lPtr->fullFitLines) {
                paintItem(lPtr, i);
            }
            notify = 1;
        }
    }
    for (; range.count>0 && position>=0 && position<total; range.count--) {
        item = WMGetFromArray(lPtr->items, position);
        if (!item->selected) {
            item->selected = 1;
            if (lPtr->view->flags.mapped && position>=lPtr->topItem
                && position<=lPtr->topItem+lPtr->fullFitLines) {
                paintItem(lPtr, position);
            }
            notify = 1;
        }
        WMAddToArray(lPtr->selectedItems, item);
        position += k;
    }
    for (i=mark2; i<total; i++) {
        item = WMGetFromArray(lPtr->items, i);
        if (item->selected) {
            item->selected = 0;
            if (lPtr->view->flags.mapped && i>=lPtr->topItem
                && i<=lPtr->topItem+lPtr->fullFitLines) {
                paintItem(lPtr, i);
            }
            notify = 1;
        }
    }

    if (notify) {
        WMPostNotificationName(WMListSelectionDidChangeNotification, lPtr, NULL);
    }
}


void
WMSelectAllListItems(WMList *lPtr)
{
    int i;
    WMListItem *item;

    if (!lPtr->flags.allowMultipleSelection)
        return;

    if (WMGetArrayItemCount(lPtr->items) ==
        WMGetArrayItemCount(lPtr->selectedItems)) {
        return; /* All items are selected already */
    }

    WMFreeArray(lPtr->selectedItems);
    lPtr->selectedItems = WMCreateArrayWithArray(lPtr->items);

    for (i=0; i<WMGetArrayItemCount(lPtr->items); i++) {
        item = WMGetFromArray(lPtr->items, i);
        if (!item->selected) {
            item->selected = 1;
            if (lPtr->view->flags.mapped && i>=lPtr->topItem
                && i<=lPtr->topItem+lPtr->fullFitLines) {
                paintItem(lPtr, i);
            }
        }
    }

    WMPostNotificationName(WMListSelectionDidChangeNotification, lPtr, NULL);
}

/*
 * Be careful from where you call this function! It doesn't honor the
 * allowEmptySelection flag and doesn't send a notification about selection
 * change! You need to manage these in the functions from where you call it.
 *
 * This will unselect all items if exceptThis is NULL, else will keep
 * exceptThis selected.
 * Make sure that exceptThis is one of the already selected items if not NULL!
 *
 */
static void
unselectAllListItems(WMList *lPtr, WMListItem *exceptThis)
{
    int i;
    WMListItem *item;

    for (i=0; i<WMGetArrayItemCount(lPtr->items); i++) {
        item = WMGetFromArray(lPtr->items, i);
        if (item!=exceptThis && item->selected) {
            item->selected = 0;
            if (lPtr->view->flags.mapped && i>=lPtr->topItem
                && i<=lPtr->topItem+lPtr->fullFitLines) {
                paintItem(lPtr, i);
            }
        }
    }

    WMEmptyArray(lPtr->selectedItems);
    if (exceptThis!=NULL) {
        exceptThis->selected = 1;
        WMAddToArray(lPtr->selectedItems, exceptThis);
    }
}


void
WMUnselectAllListItems(WMList *lPtr)
{
    int keep;
    WMListItem *keepItem;

    keep = lPtr->flags.allowEmptySelection ? 0 : 1;

    if (WMGetArrayItemCount(lPtr->selectedItems) == keep)
        return;

    keepItem = (keep==1 ? WMGetFromArray(lPtr->selectedItems, 0) : NULL);

    unselectAllListItems(lPtr, keepItem);

    WMPostNotificationName(WMListSelectionDidChangeNotification, lPtr, NULL);
}


static int
getItemIndexAt(List *lPtr, int clickY)
{
    int index;

    index = (clickY - 2) / lPtr->itemHeight + lPtr->topItem;

    if (index < 0 || index >= WMGetArrayItemCount(lPtr->items))
        return -1;

    return index;
}


static void
toggleItemSelection(WMList *lPtr, int index)
{
    WMListItem *item = WMGetFromArray(lPtr->items, index);

    if (item && item->selected) {
        WMUnselectListItem(lPtr, index);
    } else {
        WMSelectListItem(lPtr, index);
    }
}


static void
handleActionEvents(XEvent *event, void *data)
{
    List *lPtr = (List*)data;
    int tmp, height;
    int topItem = lPtr->topItem;
    static int lastClicked = -1, prevItem = -1;

    CHECK_CLASS(data, WC_List);

    switch (event->type) {
    case ButtonRelease:
        /* Ignore mouse wheel events, they're not "real" button events */
        if (event->xbutton.button == WINGsConfiguration.mouseWheelUp ||
            event->xbutton.button == WINGsConfiguration.mouseWheelDown) {
            break;
        }

        lPtr->flags.buttonPressed = 0;
        if (lPtr->selectID) {
            WMDeleteTimerHandler(lPtr->selectID);
            lPtr->selectID = NULL;
        }
        tmp = getItemIndexAt(lPtr, event->xbutton.y);

        if (tmp >= 0) {
            if (lPtr->action)
                (*lPtr->action)(lPtr, lPtr->clientData);
        }

        if (!(event->xbutton.state & ShiftMask))
            lastClicked = prevItem = tmp;

        break;

    case EnterNotify:
        if (lPtr->selectID) {
            WMDeleteTimerHandler(lPtr->selectID);
            lPtr->selectID = NULL;
        }
        break;

    case LeaveNotify:
        height = WMWidgetHeight(lPtr);
        if (lPtr->flags.buttonPressed && !lPtr->selectID) {
            if (event->xcrossing.y >= height) {
                lPtr->selectID = WMAddTimerHandler(SCROLL_DELAY,
                                                   scrollForwardSelecting,
                                                   lPtr);
            } else if (event->xcrossing.y <= 0) {
                lPtr->selectID = WMAddTimerHandler(SCROLL_DELAY,
                                                   scrollBackwardSelecting,
                                                   lPtr);
            }
        }
        break;

    case ButtonPress:
        if (event->xbutton.x <= WMWidgetWidth(lPtr->vScroller))
            break;
        if (event->xbutton.button == WINGsConfiguration.mouseWheelDown ||
            event->xbutton.button == WINGsConfiguration.mouseWheelUp) {
            int amount = 0;

            if (event->xbutton.state & ControlMask) {
                amount = lPtr->fullFitLines-(1-lPtr->flags.dontFitAll)-1;
            } else if (event->xbutton.state & ShiftMask) {
                amount = 1;
            } else {
                amount = lPtr->fullFitLines / 3;
                if (amount == 0)
                    amount++;
            }
            if (event->xbutton.button == WINGsConfiguration.mouseWheelUp)
                amount = -amount;

            scrollByAmount(lPtr, amount);
            break;
        }

        tmp = getItemIndexAt(lPtr, event->xbutton.y);
        lPtr->flags.buttonPressed = 1;

        if (tmp >= 0) {
            if (tmp == lastClicked && WMIsDoubleClick(event)) {
                WMSelectListItem(lPtr, tmp);
                if (lPtr->doubleAction)
                    (*lPtr->doubleAction)(lPtr, lPtr->doubleClientData);
            } else {
                if (!lPtr->flags.allowMultipleSelection) {
                    if (event->xbutton.state & ControlMask) {
                        toggleItemSelection(lPtr, tmp);
                    } else {
                        WMSelectListItem(lPtr, tmp);
                    }
                } else {
                    WMRange range;
                    WMListItem *lastSel;

                    if (event->xbutton.state & ControlMask) {
                        toggleItemSelection(lPtr, tmp);
                    } else if (event->xbutton.state & ShiftMask) {
                        if (WMGetArrayItemCount(lPtr->selectedItems) == 0) {
                            WMSelectListItem(lPtr, tmp);
                        } else {
                            lastSel = WMGetFromArray(lPtr->items, lastClicked);
                            range.position = WMGetFirstInArray(lPtr->items,
                                                               lastSel);
                            if (tmp >= range.position)
                                range.count = tmp - range.position + 1;
                            else
                                range.count = tmp - range.position - 1;

                            WMSetListSelectionToRange(lPtr, range);
                        }
                    } else {
                        range.position = tmp;
                        range.count = 1;
                        WMSetListSelectionToRange(lPtr, range);
                    }
                }
            }
        }

        if (!(event->xbutton.state & ShiftMask))
            lastClicked = prevItem = tmp;

        break;

    case MotionNotify:
        height = WMWidgetHeight(lPtr);
        if (lPtr->selectID && event->xmotion.y>0 && event->xmotion.y<height) {
            WMDeleteTimerHandler(lPtr->selectID);
            lPtr->selectID = NULL;
        }
        if (lPtr->flags.buttonPressed && !lPtr->selectID) {
            if (event->xmotion.y <= 0) {
                lPtr->selectID = WMAddTimerHandler(SCROLL_DELAY,
                                                   scrollBackwardSelecting,
                                                   lPtr);
                break;
            } else if (event->xmotion.y >= height) {
                lPtr->selectID = WMAddTimerHandler(SCROLL_DELAY,
                                                   scrollForwardSelecting,
                                                   lPtr);
                break;
            }

            tmp = getItemIndexAt(lPtr, event->xmotion.y);
            if (tmp>=0 && tmp!=prevItem) {
                if (lPtr->flags.allowMultipleSelection) {
                    WMRange range;

                    range.position = lastClicked;
                    if (tmp >= lastClicked)
                        range.count = tmp - lastClicked + 1;
                    else
                        range.count = tmp - lastClicked - 1;
                    WMSetListSelectionToRange(lPtr, range);
                } else {
                    WMSelectListItem(lPtr, tmp);
                }
            }
            prevItem = tmp;
        }
        break;
    }
    if (lPtr->topItem != topItem)
        WMPostNotificationName(WMListDidScrollNotification, lPtr, NULL);
}


static void
updateGeometry(WMList *lPtr)
{
    lPtr->fullFitLines = (lPtr->view->size.height - 4) / lPtr->itemHeight;
    if (lPtr->fullFitLines * lPtr->itemHeight < lPtr->view->size.height - 4) {
        lPtr->flags.dontFitAll = 1;
    } else {
        lPtr->flags.dontFitAll = 0;
    }

    if (WMGetArrayItemCount(lPtr->items) - lPtr->topItem <= lPtr->fullFitLines) {
        lPtr->topItem = WMGetArrayItemCount(lPtr->items) - lPtr->fullFitLines;
        if (lPtr->topItem < 0)
            lPtr->topItem = 0;
    }

    updateScroller(lPtr);
}


static void
didResizeList(W_ViewDelegate *self, WMView *view)
{
    WMList *lPtr = (WMList*)view->self;

    WMResizeWidget(lPtr->vScroller, 1, view->size.height-2);

    updateGeometry(lPtr);
}


static void
destroyList(List *lPtr)
{
    if (lPtr->idleID)
        WMDeleteIdleHandler(lPtr->idleID);
    lPtr->idleID = NULL;

    if (lPtr->selectID)
        WMDeleteTimerHandler(lPtr->selectID);
    lPtr->selectID = NULL;

    if (lPtr->selectedItems)
        WMFreeArray(lPtr->selectedItems);

    if (lPtr->items)
        WMFreeArray(lPtr->items);

    wfree(lPtr);
}